Conductor cable



June 9, "1936 w. T. WELLS. 2,043,400

CONDUCTOR CABLE Filed March 27, 1933 @No1/croi? 2 /EL Earn/0 (bww/v6 NVEN To@ Patented June 9, 1936 PATENT o-FFlcE CONDUCTOR CABLE Walter T. Wells, Los Angeles, Calif., assigner to The Technicraft Englneerlng Corporation, Los Angeles, Calif., a corporation of California Application March 27, 1933, Serial No. 662,901 12 claims. (ci. 17a-zes) The present invention is a conductor cable. The structure hereinafter described is a special-purpose cable and is designed for use in connection with electrically operated devices which must operate while submerged to great depths and under conditions of extreme hvdrostatic pressure. Y

In the iiring of explosive charges, in deep we11sit is desirable to ignite said charges by 10 electrical'energy, transmitted from a source at the mouth of the well, through a c'able which must be several thousand feet in length.

Cable for this type of service must be built to withstand pressures and strains to which conventional haulage or hoisting wire rope structures are subjected.

As an example, an oil well casing is to be per- Iorated -by gun-re and a type of gun is employed in which thermal elements are imbedded in explosive charges within the gun, and such charges are to be fired at intervals of time and distance throughout a'given zone in the length of the casing.

Cable employed in this instance-must have sumcient tensile strength to permit the suspension of great lengths of cable and in addition to its own weight it must also support a tool attached to the lower end of the cable, and must have, as an additional factor of safety, suiiicient excess strength to retrieve the tool should it become lodged in sand or otherwise impeded in its operation.

As the cable must be a conductor of electrical energy, an inner conductor member must be so insulated that water will not contact the wire,

or wires, to be energized, and the insulation employed must be so compacted, when formed. as to be entirely free from voids and to withstand extreme hydrostatic pressure.

Such insulation must, if the cable is to be serviceable for the uses mentioned, have a degree of flexibility as well as inherent qualities of adhesiveness to compensate for stretch-and-return movement within, and throughout the length of, the cable.

I have found rubber to be impractical for use in such insulation as it contains microscopic voids which open under external hydrostatic pressure, and the sulphur content of rubber deteriorates and renders the insulation ineiIective.

Spirally wrapped fabric, whether impregnated or not, will not withstand such pressure and becomes saturated so that a short is unavoidable.

I have discovered that an asphaltic compound pcssesses the requisite characteristics for remedying the defects of conventional insulative materials but the specific nature of the compound is not important as long as it possesses the l requisite characteristics.

In the accompanying drawing, Figure 1 is side 5 elevation of my improved cable, showing the laminae as broken away, successively to illustrate the composite structure.

Figure 2 is a transverse section of Figure 1, taken on the line III-II of said gure, and 10 Figure 3 is a diagrammatic ligure illustrating lines of force applied to a core by an outer stranded lay.

Referring 4to the drawing, the numeral -I indicates a conductor wire, preferably of copper. 15 Said conductor I is provided with a suitable exible dielectric coating and in the form shown is enamelled, as indicated at 2, with as heavy an insulative coat as it is possible to give it.

The enamel used is of very high dielectric 20 strength and will not chip or crack from the conductor when subjected to severe bending tests and is, therefore, flexible enough to expand and contract with the conductor.

The enamelled wire is then covered with a 25 .-tubular covering 3 of closely woven fabric, preferably cotton, said tubing being what is technically known as a ten-two braid. I

A second or intermediate covering I o f the same material and structure is snugly overlaid 30 on the inner tubing l, and an outer vcovering 6 is closely woven to overlie and enclose theinner and intermediate coverings and is formed in the same manner.

This triple-covered wire is next drawn through 35 a container (not shown) in which is a quantity of insulative compoundfand said compound is maintained under a degree of pressure suilicient Y to cause it to penetrate the fabric layers and is heated to a degree whereby, when extruded from 40 the container, it will have entirely impregnated the voids and interstices of the three-ply covering 3, l, and 6, and will build up to substantially cylindrical form, a layer greater in diameter than the largestvof said coverings as shown at l. At 45 high temperature this material is sticky and after penetrating the coverings), 4 andl 6, adheres tightly to the enamel 2 or other suitable dielectric coating used.

` The consistency andmelting point of the com- 5 0 pound are so predetermined as to produce at normal temperatures a dense, flexible, and a semi-plastic or malleable core impervious to water and practically insoluble in water, oil, gasoline or the various ingredients of crude oil.

., major part of the diameter of the cable.

An .outer lay of stranded steel is wound around said core and comprises six strands 8, contain'- ing seven wires each, said wires being designated at 9 in the drawing. r I'he wires 9 are twisted, the strands 8 are twisted in reverse direction, and each of said strands is pre-formed, that is to say, is helically formed before being twisted together, to insure a close wiap around core 1, and also to eliminate what is known as initial stretch and the tendency to twist in the newly finished cable. This helical pre-forming operation is illustrated in dotted lines at il in Figure l.

When the outer lay of strands 8 is applied to the core 1, by machines well known in cable manufacture, the constrictional force of the strands 8 imbeds the wires' 9 in the malleable core 1, as illustrated at I2, Figures' 1 and 2, greatly retarding any slippage between the core and the outer lay and, in addition, the insulative material adheres to the wires forming the strands 8.

It will be seen that the core of my cable is solid, that it precludes the possibility of intrusion of water or oil to the conductor I, and that a body of asphaltic material is interposed between, and caused to adhere to, the outer lay and the woven fabric which will insure simultaneous longitudinal movement of the members without applying undue stress to the woven coverings or to the conductor I, said members elongating and contracting as a unit.

My cable has one advantage not found in other structures, commonly employed for the purposes cited, to-wit:

The convolute lndentations I2 in the malleable core 1 engage both the strands 8 and the oppo- 'sitely twisted wires l in a manner affording a maximum frictional resistance to slippage between the outer lay and the core and in addition t o this the structure is automatically eifective to re-seal the duid-tight bond at each run `ol? the cable to great depths in deep wells.

The heat commonly encountered at such depths 1s sumcient te soften the core 1 and increase its plasticity so that the constrictional force of the strands of the outer lay forces the pliant insulative material into ridges Il, Figure 3, which entirely fill the spaces between contiguous members of said outer lay. The lines of force in this operation are' illustrated by arrows in Figure 3.

It should be noted that the strands 8 are few in number and therefore necessarily occupy Tt'ii: insures, what is known in the rope-making art, as a lpronounced "key-Stoning effect"; that is, the strands tend to wedge against each other when the rope is flexed and maintain theirv podtion around thecore. When the strands exceed eight in number the key-stoning effect becomes less pronounced and as a result the core tends to push through or -separate the strands when the rope is flexed. This is particularly true when the rope is wound on drums and passed repeatedly over sheaves. It is absolutely mandatory for successful operation of my special conductor core wire rope that it be capable of measuring up in all respects to standard wire rope of the haulage or hoisting type of the same diameter and grade of steel. In fact, this is completely accomplished with the construction herein described, for nei- 'ther my special core nor a conventional hemp core adds to the strength of the wire rope. My special core is no larger than the conventional hemp core'used in the standard hoisting, haulage or transmission ropes and because of the fabric servings and semi-plastic material is capable of conforming to the presented surfaces of the rope strands in practicallythe same manner as the hemp core. In other words my conductor core wire rope can be used to accomplish any function of a conventional wire rope of the same size with the additional feature of passing current between extremities of the rope so that an electrical tool may be both suspended and operated from the end of the cable.

I claim:

1. A conductor cable, substantially as described, comprising a conductor of electrical energy, provided with a flexible dielectric coating, lamina tions of woven fabric surrounding said conductor, a Ylayer of malleable, moisture-proof material surrounding said fabric and completely illing the voids therein, and' an outer lay composed of a plurality of stranded wires.

2. A conductor cable, substantially as described, comprising a conductor of electrical energy, provided with a exible dielectric coating, laminations of woven fabric surrounding said conductor, a layer of malleable, moisture-proof material surrounding said fabric and completely filling the voids therein, and an outer lay composed of a plurality of stranded wires, said strands and said wires being so pre-formed as to insure a tight wrap in the finished cable.

3. A cable of the character described, comprising an outer lay of stranded wires, forming the weight-supporting part of said cable, a dielectriccoated conductor within said lay, a woven covering for said conductor, and a tubular layer of malleable, moisture-proof material vinterposed between said lay and said conductor, impregnating the weave of said covering, and adhering to the members composing said stranded lay.

4. .A weight-supporting cable for carrying electricity, comprising a conductor of electrical energy, provided with a flexible dielectric coating, a lamination of woven fabric surrounding vsaicl dielectric coating and enclosing said, conductor, a layer of malleable, moisture-proof material surrounding said fabric and completely lling the voids therein, and an outer lay composed of a plurality of stranded wires, said stranded wires being preformed beforelaying up in the nished cable.

5. A conductor core wire rope comprising: a relatively small core including. a conductor. a woven fabric thereabout, a iluid resistant semiplastic material thoroughly impregnating the fabric with the excess forming an external sealing layer;I and a plurality of multiple wire strands laid about the core, said strands occupying the major diameter of the wire rope.

6. A hoisting and conductor cable camprising a conductor core, a dielectric coating therefor, a 'weight supporting spirally stranded wire outer sheath occupying at least one-half the diameter of the cable, and a layer of semi-plastic fluid resistant material surrounding the core and adhering to the sheath and adapted to resist extreme hydrostatic pressures.

7. A hoisting and mnductor cable comprising a conductor core, a dielectric coating therefor, a layer of semi-plastic fluid resistant material surrounding the core andv adapted to resist extreme hydrostatic pressures, and a weight supporting spirally stranded wire outer sheath occupying at least one-half the diameter of the cable surroundfluid resistant material thoroughly impregnating the fabric and forming an external layer and adapted to resist extreme hydrostatic pressures, and a weight supporting spirally stranded wire outer sheath occupying at least one-half the diameter of the cable surrounding said layer and adhesively associated therewith.

9. A hoisting and conductor cable comprising a conductor core, a dielectric coating therefor, a woven fabric surrounding the core, semi-plastic fluid resistant material thoroughly impregnating the fabric and forming an external layer and adapted to resist extreme hydrostatic pressures, and a weight supporting spirally stranded wire outer sheath occupying at least one-half the diameter of the cable surrounding said layer and adhesively associated therewith, the strands of said sheath being pre-formed.

10. A hoisting and conductor cable comprising a conductor core, a weight supporting spirally stranded wire outer sheath occupying at least one-half the diameter of the cable, and a layer of semi-plastic uid resistant and insulating material surrounding the core and adhering to the sheath and adapted to resist extreme hydrostatic pressures.

11. A hoisting and conductor cable comprising a conductor core, a layer lof semi-plastic fluid rel sistant and insulating material surrounding the' core and adapted to resist extreme hydrostatic pressures, and a weight supporting spirally stranded wire outer sheath occupying at least one-half the diameter of the cable surrounding said layer and adhesively associated therewith, the strands of said sheath being preformed.

12. A conductor core wire rope adapted for use in oil wells including a centrally disposed conductor, a fabric covering therefor, a semi-plastic fluid resistant insulating compound impregnating the covering to an exesss to form an external sealing layer, a multiplicity of spirally Wound Wire strands enveloping the covering and embedded in the said layer, the size of the strands with respect to the core and their number being such as to exhibit a pronounced key-stoning effect, and said compound tending to increase its plasticity under the heat of operating conditions and re- .2

conform to the said strands.

WALTER. T. WELLS. 

